LANSING – Department of Community Health executive director Jim Haveman, who spearheaded the effort to expand Medicaid to 400,000 low income Michiganders, is stepping down from his job after a recent mild stroke.

He will be replaced by the department’s deputy director Nick Lyon, who has been with DCH in a variety of positions since 2003. Before that, he was the director of the state office of budget development and finance officer for the state Attorney General. He has an economics and political science degree from Yale University.

He’ll replace Haveman, who held the same position under former Gov. John Engler as well as the director of the state Department of Mental Health from 1991-96.

“It had always been my intention to stay in the position of director through 2015 but with the minor stroke I experienced on Memorial Day, Barb and I have decided it is best to re-evaluate that time table,” said Haveman, in a statement released Thursday. “This has been a difficult decision because I truly love my work.”

Haveman was instrumental in several health initiatives in the state under Gov. Rick Snyder, including the Medicaid expansion, which has enrolled 375,000 people in the past five months, and the bi-partisan Menal Health and Wellness commission.

“Director Haveman’s leadership has been instrumental as we’ve navigated an ambitious health and wellness agenda that has led to inclusive, bipartisan support to implement a number of key health initiatives that are making a real difference in Michiganders' lives,” Snyder said.